<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .page{
      font-size: 5px;
    }
    .box{
      font-size: 2em;
    }
    .title{
      width: 100rem;
      height: 100rem;
      background-color: aqua;
    }
  </style>
</head>
<body>
  <div class="page">
    <div class="box">
      <div class="title">hello</div>
    </div>
  </div>
</body>
</html>